In an ultimatum to his ministers that could result in an ugly show-down just one month after winning power, UK PM David Cameron warned his ministers today that they would have to back him on Europe or go, reportsJon Danzig.

Downing Street sources confirmed to the Telegraph this evening that Mr Cameron would expect any minister who planned to campaign for Britain to leave the EU to resign.

The Telegraph claimed that at least five ministers are known to believe that Britain should vote to leave the EU if the Prime Minister is unable to secure major reforms from Brussels. The newspaper also claimed that the Prime Minister had “rebuked” over 50 Tory MPs who have formed a group that, “will plot to take Britain out of the EU if members do not think his planned renegotiation is successful.”

Asked about the group, the Prime Minister told The Telegraph: “In the end, people have to make up their own mind. But it’ll be the public, it’ll be the people that decide, not one group of MPs or another group of MPs.”

Anger on this issue may spill over in the Tory backbenchers in the House of Commons tomorrow when there will be a debate on the EU referendum Bill.